WIN XP-SP3 RELEASE CANDIDATE & SUBINACL.EXE (FROM RESOURCE KIT)

Aloha,
I've been having difficulty with the SP3 upgrade installation which runs fully, ends with an' access denied' error message and backs out to SP2 again. A moderator in the Microsoft SP3 forum suggested I use SUBINACL.EXE to change all permissions to include my username ( I'm the administrator, anyway ).

Except, Subinacl.exe has so many '/' toggles, I don't know which parameters to use to accomplish this.

Can anyone help?

Thanks